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Topic: PDE - spherical coordinates question (polar)
Replies: 2   Last Post: Aug 21, 2013 1:14 PM

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Re: PDE - spherical coordinates question (polar)
Posted: Aug 21, 2013 1:14 PM

"Torsten" wrote in message <kv1nnj\$nj4\$1@newscl01ah.mathworks.com>...
> "Saad" wrote in message <kuvtva\$guv\$1@newscl01ah.mathworks.com>...
> > Hi,
> > I'm trying to solve the following PDE using (pdepe).
> > Does anyone have any tips on how to input the variable coefficients for this equation.
> >
> > dH/dt + 1/sinx d/dx(H^3 (sinx)^2)=0
> >
> >
> > Thanks,

>
> pdepe is suited for PDEs which contain a second-order spatial derivative (in your case, this would be an expression involving d^2H/dx^2).
> Since your equation is a first-order PDE, you will have to solve it using a different tool.
> Differentiating out, you get
> dH/dt + 3*H^2*sin(x)*dH/dx = -2*H^3*cos(x).
>
> Best wishes
> Torsten.

Thanks Torsten - I'm trying to figure out an alternative method.

-S

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